Parallels

Parallels are used to support a workpiece when clamping it in a milling vise. They are nothing more than pairs of steel rectangles that are accurately matched in height.

In use, the parallels are placed adjacent to each jaw of the milling vise and the workpiece is supported by the parallels such that the workpiece is exactly parallel with the base of the milling vise, and thus with the milling table.

The photos above show placement of the parallels in the milling vise and a workpiece supported by the parallels. The workpiece is raised up so that the sides may be milled to form a T-shaped cross section.

Parallels come in sets in which the length and thickness are common to all, with pairs varying incrementally in height. For example, I have a set of 9 pairs, 1/4" thick, 6" long and with heights varying from 3/4" to 1 3/4".

They come in a segmented wooden box. Import sets are available in the sale flyers from J&L, Enco, MSC and similar sources for $20-$40.

The set in the right-hand photo are 4" long and 1/8" thick. This is a cheap set in which only the top and bottom surfaces are ground and the sides are rough, but they are handy when the 1/4" set is too thick; i.

e. when the workpiece is less than 1/2" thickness. For thin workpieces, you can use a single parallel to support the work.

If you are just starting out and money is tight, you can mill your own parallels. I have made some from time to time from 1/4" acrylic plastic as shown in the next photo.